Sliplining cylinders require only conventional spiral welded steel pipe manufacturing equipment and machine welds. Cement mortar lining is typically applied to the cylinders at the shop, prior to transport to a job site. Installation is fast because there are no longitudinal seams to weld in the field for each of the cylinders. It is typical to install 25 to 35 Sliplining cylinders 60-inch in diameter per day.
Sliplining is another steel-based rehabilitation solution for structurally deficient Prestressed Concrete Cylinder Pipe (PCCP). With 19,000 miles of PCCP systems in the ground throughout the United States, the premature failure of these systems are being prevented using fully structural renewal methods such as steel cylinder-based Sliplining.
In Sliplining, full sections of steel pipe are inserted into the host PCCP, and once placed in the appropriate location, adjoining pipe sections are connected typically by lap welding the joints. Gasketed joints can also be specified instead. Grout is used to fill the annular space, and cement mortar lining may be applied on-site, but typically the cylinders are supplied with shop-applied cement mortar lining for improved hydraulics and corrosion protection. Sliplining can be successfully performed without man-entry of the host pipe and is ideal in most pipe diameters.
The loss of internal diameter of the host pipe is high with Sliplining compared to Relining. For a 60-inch internal diameter host pipe, 6-inches to 8-inches of flow area is typically lost when using Sliplining.